1. Field of the Invention
The present invention relates to an image recording apparatus which executes maintenance of a recording head by moving a suction nozzle contacting with or closing to the recording head surface, and a maintenance method of the recording head of the image recording apparatus.
2. Description of the Related Art
Conventional-maintenance method and mechanism of a recording head, for example, an ink jet head are to eliminate bubbles generated in an ink chamber in an ink jet head by discharging ink from an ink discharge port by pressurizing an ink supply chamber, or by absorbing bubbles from an ink discharge port by means of a suction nozzle or a cap means. This maintenance method is the same as a method of eliminating bubbles through a vent comprising an ink non-discharge nozzle provided at both ends of an ink jet head, in order to maintain the printing performance of an ink jet head, for example, when bubbles mix into an ink chamber during filling ink or other operations. This makes it possible to eliminate bubbles easily without using a special method of eliminating bubbles.
However, in this method, the suction pressure of a suction nozzle is held constant as a suction force not absorbing air or dust from an adjacent ink discharge nozzle. Therefore, this suction force of a suction nozzle is insufficient to absorb bubbles from an ink non-discharge nozzle whose passage resistance is larger than that of an ink discharge nozzle. Further, if the suction force of the suction nozzle is set to the valve for the ink non-discharge nozzle to enable to absorb bubbles, the absorbing force is too strong for the ink discharge nozzle and breaks the meniscus formed within the ink discharge nozzle.
There is another known method of absorbing bubbles through different absorbing routes by providing first and second caps in one capping member and switching them with a solenoid valve. However, absorption of bubbles through two different routes complicates the structure.
Thus, there is the need for an image recording apparatus which can perform maintenance of a recording head easily with a simple structure, and a maintenance method of the recording head of the image recording apparatus.
According to an aspect of the present invention, there is provided an image recording apparatus comprising a recording head which has an ink discharge nozzle to discharge ink and an ink non-discharge nozzle to eliminate bubbles; a suction unit which makes suction for maintenance by moving a suction nozzle on the ink discharge side of the recording head, contacting with or closing to the ink discharge nozzle surface of the recording head; and a control unit which controls the suction unit to make suction by a first suction force when the suction nozzle is in the position corresponding to the ink discharge nozzle and by a second suction force when the suction nozzle is in the position corresponding to the ink non-discharge nozzle.
Objects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention.